N-TiO2 nanoparticles embedded in silica prepared by Ti ion implantation and annealing in nitrogen

Room-temperature Ti ion implantation and subsequent thermal annealing in N₂ ambience have been used to fabricate the anatase and rutile structured N-doped TiO₂ particles embedded in the surface region of fused silica. The Stopping and Range of Ions in Matter (SRIM) code simulation indicates a Gaussian distribution of implanted Ti, peaked at ∼75 nm with a full width at half maximum of ∼80 nm. However, the transmission electron microscopy image shows a much shallower distribution to depth of ∼70 nm. Significant sputtering loss of silica substrates has occurred during implantation. Nanoparticles with size of 10-20 nm in diameter have formed after implantation. X-ray photoelectron spectroscopy indicates the coexistence of TiO₂ and metallic Ti in the as-implanted samples. Metallic Ti is oxidized to anatase TiO₂ after annealing at 600 °C, while rutile TiO₂ forms by phase transformation after annealing at 900 °C. At the same time, N-Ti-O, Ti-O-N and/or Ti-N-O linkages have formed in the lattice of TiO₂. A red shift of 0.34 eV in the absorption edge is obtained for N-doped anatase TiO₂ after annealing at 600 °C for 6 h. The absorbance increases in the ultraviolet and visible waveband.     

Sub-surface retention of Pb atoms in silicon after low-energy ion implantation and electron beam annealing

Low-energy Pb ion implantation into (1 0 0) Si and subsequent high-vacuum electron beam annealing was used to study the potential of sub-surface retention of Pb atoms after applying a high temperature annealing process. 7 keV Pb⁺ ions were implanted into p-type (1 0 0) Si at room temperature with a fluence of 4 × 10¹⁵ ions cm⁻². The implantation results in a Pb depth distribution that has a calculated Pb peak concentration of 23.9 at.% at a depth of 8.0 nm. The Pb implanted Si substrates were annealed with a high-current 20 keV electron beam at 200-700 °C for 15 s. The Pb loss by out-diffusion was measured with RBS. Key results are: (i) minimal Pb loss in samples annealed up to 400 °C, (ii) emerging out-diffusion above 400 °C, (iii) retention of Pb atoms in the near-surface region in samples annealed up to 700 °C. Comparison of the RBS data with the calculated evaporation rate of Pb under similar conditions reveals two distinctive temperature ranges in which the measured Pb loss of the implanted samples disagrees with the calculated Pb loss: (1) Pb atoms diffused out of the samples at a higher rate in the temperature range up to 400 °C and (2) the Pb atoms diffused out of the samples at a much slower rate above 450 °C. Both phenomena are attributed to the ion implantation process.     

TiO2 nanofilm growth by Ti ion implantation and thermal annealing in O2 atmosphere

TiO2 nanofilms on surface of fused silica were fabricated by Ti ion implantation and subsequent thermal annealing in oxygen ambience. The silica glasses were implanted by 20 k V Ti ions to 1.5 × 1017ions/cm2 on an implanter of metal vapor vacuum arc(MEVVA) ion source. Effects of annealing parameters on formation,growth and phase transformation of the TiO2 nanofilms were studied in detail. Optical absorption spectroscopy,Raman scattering spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy measurements were done to figure out formation mechanism of the TiO2 nanofilms.The formation of TiO2 nanofilms was due to out-diffusion of the implanted Ti ions to the substrate surface,where they were oxidized into TiO2 nanoparticles. Formation, phase, and thickness of the TiO2 nanofilms can be well tailored by controlling annealing parameters.     

离子注入对电器触头性能的影响

对两种电器触头注入1×10~(17)/cm~2的氮离子,然后做低压电器通断试验,测量了触头的重量损失、温升、接触电阻、触头材料转移等参数,发现离子注入方法处理对电器触头性能有不同程度的改善。     

Effect of annealing on structure and hardness of oxygen-implanted layer on Ti6Al4V by plasma-based ion implantation

Ti6Al4V was treated by oxygen plasma-based ion implantation at the voltage pulses of −30 and −50 kV with a constant fluency of 0.6 × 10¹⁷ O/cm². After implantation, the annealing in vacuum was applied to the implanted samples to control phase structure of the implanted layer. The higher voltage implantation forms nano-size rutile in the implanted layer, but the subsequent annealing at 600 °C induces the resolution of the previous rutile. Although, the lower voltage implantation does not lead to rutile, the annealing can precipitate anatase and rutile in the implanted layer. The higher voltage implantation results in a higher hardness of the implanted layer. The annealing at 500 °C leads to an apparent increase in hardness of the implanted layer, but the annealing at 600 °C induces a rapid decrease in hardness.     

Ohmic contacts on n-type layers formed in GaN/AlGaN/GaN by dual-energy Si ion implantation

Electrical properties of Si-implanted n-type GaN/AlGaN/GaN layers and contact resistances of ohmic electrodes (TiAl) formed on these layers have been examined. Experimental results have clearly shown that ohmic electrodes with a low specific-contact resistance of 1.4 × 10^?7 Ω cm² can be fabricated on the n-type layer having a low sheet resistance of 145 Ω/sq, which has been formed by the dual-energy Si ion implantation (80 keV:1.01 × 10¹⁵/cm² + 30 keV:1.6 × 10¹⁴/cm²) and subsequent annealing at 1200 °C for 2 min using a Si₃N₄ layer as an encapsulant.     

Formation of Si/SiC multilayers by low-energy ion implantation and thermal annealing

Si/SiC multilayer systems for XUV reflection optics with a periodicity of 10-20 nm were produced by sequential deposition of Si and implantation of 1 keV ions. Only about 3% of the implanted carbon was transferred into the SiC, with a thin, 0.5-1 nm, buried SiC layer being formed. We investigated the effect of thermal annealing on further completion of the carbide layer. For the annealing we used a vacuum furnace, a rapid thermal annealing system in argon atmosphere, and a scanning e-beam, for different temperatures, heating rates, and annealing durations. Annealing to a temperature as low as 600 °C resulted in the formation of a 4.5 nm smooth, amorphous carbide layer in the carbon-implanted region. However, annealing at a higher temperature, 1000 °C, lead to the formation of a rough poly-crystalline carbide layer. The multilayers were characterized by grazing incidence X-ray reflectometry and cross section TEM.     

PⅢD技术制备Ti/DLC纳米多层薄膜

采用等离子体浸没离子注入与沉积(PⅢ&D)技术在2Cr13钢表面制备了Ti/DLC纳米多层薄膜.分析了膜层的微观结构和机械特性.实验结果表明:纳米多层膜具有完整、清晰的调制层结构,薄膜的显微硬度均得到明显的提高.硬度较低的膜层具有较好的膜基结合强度和优良的摩擦性能,从综合性能看:纳米多层薄膜保持了类金刚石(DLC)薄膜低摩擦系数的特性,具有良好的承载能力以及膜一基结合特性.     

PIIID技术制备Ti/DLC纳米多层薄膜

采用等离子体浸没离子注入与沉积（PIII＆D）技术在2Cr13钢表面制备了Ti／DLC纳米多层薄膜,分析了膜层的微观结构和机械特性。实验结果表明：纳米多层膜具有完整、清晰的调制层结构,薄膜的显微硬度均得到明显的提高,硬度较低的膜层具有较好的膜基结合强度和优良的摩擦性能,从综合性能看：纳米多层薄膜保持了类金刚石（DLC）薄膜低摩擦系数的特性,具有良好的承载能力以及膜-基结合特性。     

The effects of the annealing time on helium implantation in Si

The modifications induced in silicon samples by helium implantation before and after isothermal annealing at 673 K have been investigated. The surface morphology has been detected by atomic force microscopy. A hillock structure is observed on the sample surface before and after annealing for 5-10 min. Surface blister formation is observed with an increasing annealing time. The variation of crystal damage with annealing time has been investigated by Rutherford backscattering/channeling. The intensity of the damage peak first increases with annealing time, reaches maximum at an annealing time of 60 min and then decreases. Helium-induced bubbles and residual defects have been observed by transmission electron microscopy, which shows that dislocations are close to the bubbles.     

Channeling effects and defect accumulation in ion implantation

In channeling implantation range and damage distributions and the dechanneling probability are strongly influenced by lattice vibrations, by a thin amorphous surface layer, by radiation-induced defect production during ion bombardment and by pre-existing defects. This is demonstrated in the example of100 channeling implantation of 80 keV boron into silicon using our binary collision code Crystal-TRIM. The comparison with experimental data shows that the simple model of defect accumulation used is sufficient to simulate the dose dependence of the range profiles. However, the simulations do not produce realistic damage distributions for high-dose implantation.     

Controlled localised melting in silicon by high dose germanium implantation and flash lamp annealing

High intensity light pulse irradiation of monocrystalline silicon wafers is usually accompanied by inhomogeneous surface melting. The aim of the present work is to induce homogeneous buried melting in silicon by germanium implantation and subsequent flash lamp annealing. For this purpose high dose, high energy germanium implantation has been employed to lower the melting temperature of silicon in a predetermined depth region. Subsequent flash lamp irradiation at high energy densities leads to local melting of the germanium rich buried layer, whereby the thickness of the molten layer depends on the irradiation energy density. During the cooling down epitaxial crystallization takes place resulting in a largely defect-free layer. The combination of buried melting and dopant segregation has the potential to produce unusually buried doping profiles or to create strained silicon structures.     

Formation of Au nanoparticles in sapphire by using Ar ion implantation and thermal annealing

In this paper, we present results of the synthesis of gold nanoclusters in sapphire, using Ar ion implantation and annealing in air. Unlike the conventional method of Au implantation followed by thermal annealing, Au was deposited on the surface of m- and a- cut sapphire single crystal samples including those pre-implanted with Ar ions. Au atoms were brought into the substrate by subsequent implantation of Ar ions to form Au nanoparticles. Samples were finally annealed stepwisely in air at temperatures ranging from 400 to 800 °C and then studied using UV-vis absorption spectrometry, transmission electron microscopy and Rutherford backscattered spectrometry. Evidence of the formation Au nanoparticles in the sapphire can be obtained from the characteristic surface plasmon resonance (SPR) absorption band in the optical absorption spectra or directly from the transmission electron microscopy. The results of optical absorption spectra indicate that the specimen orientations and pre-implantation also influence the size and the volume fraction of Au nanoparticles formed. Theoretical calculations using Maxwell-Garnett effective medium theory supply a good interpretation of the optical absorption results.     

铁与钛离子注入对杉木幼苗叶绿素荧光参数及叶绿素含量的影响

用能量50 ke V的Fe+与Ti+,以不同注量D1(1.0×1015 cm-2)、D2(5.0×1015 cm-2)、D3(1.0×1016 cm-2)和D4(5.0×1016 cm-2)处理杉木种子,并采用丙酮浸泡提取法测定幼苗叶绿素含量,荧光测定仪对荧光参数进行测定。结果显示,Fe+注入较Ti+注入对初始荧光值(Fi)及可变荧光(Fv)的影响更为显著,导致叶片的Fi和Fv上升,而Ti+处理中Fi和Fv与对照比较变化不大。两种离子注入处理中PSII原初光能转化效率(Fv/Fmax)和PSII潜在的光化学活性(Fv/Fi)与对照组相比均没有明显差异。随注量的增大,Fe+处理下幼苗受到光抑制,荧光光化学淬灭系数qP曲线低于对照组而非光化学淬灭qN曲线均高于对照组,Ti+注入在D1、D2和D3时对幼苗光合具有促进作用,D1时最佳。Fe+注入导致叶绿素含量降低,叶绿素a/b值升高,显示出对叶绿素产生的抑制作用;相反Ti+注入对叶绿素含量具有一定的促进作用,可提高光合作用的能力。     

离子注入加工番茄和茄子种子的生物学效应

用6种不同注量的低能氮离子(N+)注入加工番茄87-5种子,出苗率有所降低,但M1代平均单株座果数增加,早熟20d。M2代仍表现出早熟、抗病和较强的生长势。根据两年的试验结果,从加工番茄的早熟性、抗病性、丰产性和品质因素等方面综合分析,采用6×1016cm-2(60次脉冲)的N+注入加工番茄87-5种子,可获得显著的当代生物效应和第二代生物效应。在低能N+注入五叶茄种子的M1代中出现了多纵沟的变异果,形如去皮的柚子,单收此果种子进行种植,在M2代分离的果形中,出现了同时具备抗病、紫红、脐小、果大等优良性状的变异果,最大单果重1.53kg,为育种提供了珍贵材料。     

离子注入微型半导体探测器的研制

国际上最早使用的微型探测器是盖革-缪勒计数器,并用它首次对活体内的肿瘤进行了测试。六十年代以来,它逐步为半导体探测器所代替。七十年代以来,微型半导体探测器已广泛地用于血流动力学、肺功能研究以及食管、胃和眼睛等体内和体表器官的诊断。我们也曾用半导体硅探测器对甲状腺节结进行过测试,效果良好。     

高剂量注入中离子溅射的影响

在离子注入材料改性的研究过程中(金属、绝缘材料和光学材料等),在许多场合下,要求注入的元素(如Fe中注入N、Y、Ph和Sn等)在靶子中占百分之几的含量,这就要求注入剂量高达10~(17)/cm~2到10~(12)/cm~2。由于离子注入的溅射效应在低能和大剂量注入中是相当明显的,因此,对这些元素高剂量注入后的杂质分布、溅射系数、溅射厚度和靶子中杂质的收集量做一分析是十分重要的。